题目链接:http://poj.org/problem?id=3252 题意: 一个数的二进制表示中0的个数大于等于1的个数则称作Round Numbers.求区间[L,R]内的 Round Numbers的个数. 思路: int c[N][N]; void init(){    int i,j;    FOR0(i,N)     {        c[i][0]=c[i][i]=1;        for(j=1;j<i;j++) c[i][j]=c[i-1][j-1]+c[i-1][j]; …

C. Beautiful Numbers 题目连接: http://www.codeforces.com/contest/300/problem/C Description Vitaly is a very weird man. He's got two favorite digits a and b. Vitaly calls a positive integer good, if the decimal representation of this integer only contains…

1095 - Arrange the Numbers Consider this sequence {1, 2, 3 ... N}, as an initial sequence of first N natural numbers. You can rearrange this sequence in many ways. There will be a total of N! arrangements. You have to calculate the number of arrangem…

/** 大意: 给定16进制数的16个字母,,求第k大的数,,要求数的长度最大为8.,并且每个数互不相同. 思路: 从高到低挨个枚举,每一位能组成的排列数 ,拿最高位来说,能做成的排列数为15*A(15,len-i) 第二位 A(14,len-2)..这样就可以找到k大的数的长度 接下来 .找第k大的数.同上理 ,挨个枚举每一位即可..若加上该位的排列数大于k,则该位就是这个数,继续枚举下一位 **/ /** 大神思路 首先确定数字串的长度Len:从大到小枚举Len,每个Len下有15*P(15…

Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 7558   Accepted: 2596 Description The cows, as you know, have no fingers or thumbs and thus are unable to play Scissors, Paper, Stone' (also known as 'Rock, Paper, Scissors', 'Ro, Sham, Bo'…

Round Numbers Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 8590   Accepted: 3003 Description The cows, as you know, have no fingers or thumbs and thus are unable to play Scissors, Paper, Stone' (also known as 'Rock, Paper, Scissors',…

C. Kyoya and Colored Balls Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/554/problem/C Description Kyoya Ootori has a bag with n colored balls that are colored with k different colors. The colors are labeled from 1 to k.…

Round Numbers Time Limit : 4000/2000ms (Java/Other)   Memory Limit : 131072/65536K (Java/Other) Total Submission(s) : 11   Accepted Submission(s) : 8 Problem Description The cows, as you know, have no fingers or thumbs and thus are unable to play Sci…

POJ 3252:Round Numbers Time Limit: 2000MS Memory Limit: 65536K Total Submissions: 10099 Accepted: 3669 Description The cows, as you know, have no fingers or thumbs and thus are unable to play Scissors, Paper, Stone' (also known as 'Rock, Paper, Sciss…

一般用dfs来做 最简单的一种: 17. Letter Combinations of a Phone Number Given a digit string, return all possible letter combinations that the number could represent. A mapping of digit to letters (just like on the telephone buttons) is given below. Input:Digit s…